Telkom charging incorrectly on SmartVoice packages

Telkom converted me to their SmartVoice Basic last year for ***. One of the product features/benefits at the time (still is) up to 3000 minutes on-net, ie: To Telkom landline and mobile #s free of charge but subject to FUP But my monthly a/c's show that I'm paying for these calls - not all but some. Have paid for such in Sept/Nov/Dec '19 and Jan/Feb/March/April & June '20. Went to Telkom store at Eastate to day to enquire. Agent there could not tell me why Also, work for a person on SmartVoice 300 ***) also with 3000 minutes (FUP) Telkom to Telkom and 300 minutes free calls to other networks. We drew her latest a/c today and it contains landline can mobile calls to other networks for which she was charged. Here also, not all but some. For her too, this has been happening across some months since she was migrated last year